PC shuts down within 3 seconds

[Slips]

Hi, recently my pc has had an issue with simply powering on. Im pretty acquainted with pc trouble shooting, ive had numerous pc issues before and have been able to fix each one of them but this one has left me clueless and frustrated. Heres exactly what happens. Once i turn on the mains, and i mean the mains at the wall socket, the pc powers on by itself (i dont even need to press the case buttons). But then it goes off after 3-4 seconds. No beeps , no new hardware installed whatsoever. This has just happened all of a sudden. Once it goes off, however much i jam the case button it simply wont turn on again, but if i turn off the mains and turn it on again, once again it turns on for a few seconds, goes off and the case button doesnt respond at all. Ive tried rewiring and removing and fixing all the ram chips and cards again, but it didnt help. Applied some fresh thermal paste but that didnt work either. Im really helpless on this one, anyone ever experienced this before? Thanks in advance. Heres my spec btw :

Amd 3700+ 64bit
2gb transcend ram
xfx 7600gt
gigabyte mb
2x case coolers
stock heatsink
1x 80gb sata hdd
1x dvd writer
400w psu

[goobimama]

Try removing the Motherboard battery with the main's power off. Although it pretty much looks like a power supply problem to me.

[sidewinder]

^^ +1
Try another psu to check.Looks like a PSU issue to me too !
Also..recheck the mobo front panel connectors too..something is short circuiting !

[The Conqueror]

I think there is a problem with power supply.

[smile]

Change ur SMPS ...........problem lies there

[pimpom]

Your Power switch is probably stuck in the ON position. Either the cabinet button is stuck in the depressed position or the actual switch inside the cabinet is stuck.

To find out, pull out the power switch connector from the motherboard front panel header and replace it with the RESET connector. If my diagnosis is correct, your computer will no longer turn on by itself when you apply mains power, and you should now be able to turn your computer on and off normally with the Reset switch.

Explanation: Your computer turns off by itself after 4 seconds because the usual default BIOS setting is to turn off power by pressing the power button for 4 seconds.

P.S.: My %@#!!& BSNL broadband has been down for more than three days now. Otherwise I would have seen this thread earlier. Right now I'm using dial-up for essential activities.

[Sooraj_digit]

your power button on your cabinet is faulty FOR SURE replace it. if this cant be done then pull out all the front panel(POWER switch, RESET switch, HDD led switch, POWER led switch) connectors from the mother board and reinsert them make sure to use your MOTHER MANUAL while doing this, wrong connctions might cause HARM. If this doesnt help then you have to get new power button and all the set these are not that expensive. Even one of my friends had same problem and was solved by this solution there is very few probablities of a PSU problem so chill this is not a big problem

[goobimama]

I highly doubt it is the Power button, but I would try and check that as well. Does your PSU work without the motherboard?

[ravi_9793]

Open cabinet from one side, and run the system.
The cause may be overheating.

Also, clean processor fan, SMPS fan and cabinet fan.

[goobimama]

^^ 3 Seconds? No way it is overheating. Any CPU can boot at least till the login screen before going into thermal overload.

[ravi_9793]

Another possible cause can be lower SMPS wattage. You can try a higher wattage SMPS say like 600 watt.

[Sooraj_digit]

Originally Posted by goobimama

^^ 3 Seconds? No way it is overheating. Any CPU can boot at least till the login screen before going into thermal overload.

I AGREE.........

Originally Posted by goobimama

I highly doubt it is the Power button, but I would try and check that as well. Does your PSU work without the motherboard?

It is definately the fault of the front panel power switch cuz, when you power the psu the faulty power switch intiates the boot command for pc.... and then again it initiates shut down cuz the button is always making the mobo feel that the power button is always pressed and never been released.

[pimpom]

I wonder where the OP went. Registered to ask the question, gave up when nobody answered immediately and never came back?

It's helpful for the community as a whole when the OP reports which suggestion worked and which didn't.

[Sooraj_digit]

Originally Posted by pimpom

I wonder where the OP went. Registered to ask the question, gave up when nobody answered immediately and never came back?

It's helpful for the community as a whole when the OP reports which suggestion worked and which didn't.

Sure man, u r right.... he should must have atleat posted once...... we're feeling dumb...

[Slips]

Thanks for the replies guys but although ive somewhat fixed the previous one i have another problem now. I recently purchased a new case and a psu aswell. My PC boots, the power led and hdd led light up, disc drive led flashes, but i get no video and no beeps, ive tried using just either one of the two ram sticks, and ive tried onboard video. Nothing worked. My only guess is that my motherboard is probably fried? I have been reckless a lot of times and fixed / removed stuff from my case without discharging possible static, but is this what happens when a motherboard is damaged? Yeah and another thing i forgot to mention, since i didnt think it was too relevant, from my knowledge. If i touch any metal part connected to my pc and i mean anything, front usb, any side of the case thats metal, a metal phone connected to my pc , i get a nasty shock, one as powerful as shoving a finger into a mains socket . I know it was ignorant to leave that issue alone but i didnt think it could kill my pc, just assumed theres a grounding fault in that socket that would just give me shocks and not really harm my pc.

[pimpom]

You are partially correct in that getting a shock from the metal case is probably caused by a faulty ground path. The PSU has a filter for spikes and RF interference that leaks mains current through the cabinet. That leakage is supposed to drain out harmlessly through your mains ground line to actual earth.

Some people are more sensitive to such leakages than others, and the severity of the shock also depends on how dry your skin is. If you have moist skin or have been sweating, that greatly reduces your body's electrical resistance and increases the shock you feel.

Whether the leakage harms your hardware depends on the leakage path. Left alone, it won't do any harm. But if you touch the cabinet and some sensitive part of your computer at the same time, it can certainly cause damage. Many parts of your computer can stand only a few volts, but that's more than 200 volts flowing from the mains.

Oh, and just how did you solve your initial problem?

[amitash]

i too had that same problem with all the lights and fans spinning for a second and then the pc not turning on...
heres wat i did:
1)removed all the connected devices on the mobo except for the procy and ram and powered it on...it worked fine.
2)Connected my Wlan card...still worked fine
3)connected DVD drive and all fans...still working
4)connected my gfx card Bingo!!PC didnt turn on...somehow there was something wrong with my card i got a replaced piece and everything worked fine.

[Slips]

Oh, and just how did you solve your initial problem?

I just picked up a new case and psu, not sure which one of those fixed the problem.

Anyways im going to try what amitash has suggested , ill post once i give it a try.

[pimpom]

Originally Posted by Slips

I just picked up a new case and psu, not sure which one of those fixed the problem.

That practically confirms that it was the switch. The theory fits the symptoms perfectly; besides, I've seen a few actual cases.

[Slips]

Ok theres something i should have mentioned earlier too. When i turn on the mains now i get no video , no beeps, but the case turns on by itself, i dont need to press the case power button, also it doesnt respond to the button when i keep it pressed (to turn it off). This is a new case btw, and this problem was somewhat common to the previous case too(Post #1). As of now heres what ive tried :

I tried the below after disconnecting all drives.


Removed video card and tried onboard / reseating / no video etc , all have the same effect, no video and monitor LED just keeps on blinking. No beeps.

Tried booting with 1 of 2 ram chips and tried booting with none. No beeps.

The only thing left that i booted with was the cpu and the mb. No video , no beeps once again.

Seeing that my previous case also had an issue with turning on / off and no other component seems to be a problem here, i think i can safely conclude that my motherboard is probably gone, my guess would be the that part of the mb handling the case has got damaged along with some other main component inside, resulting in no response to the case switch and no boot. Although im going to have the mb and processor tested once again at a local store before confirming which one to replace. Im guessing the cause of this was a power fault / surge of some sort.

Thanks all for the help.